
/*
import java.util.*;

public class Main4 {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        CourseManagementSystem cms = new CourseManagementSystem();
        int ops = sc.nextInt();
        for (int i=0;i<ops;i++) {
            String op = sc.next();
            if (op.equals("add"))
                cms.add(sc.nextInt(), sc.nextInt());
            else if  (op.equals("delete"))
                cms.delete(sc.nextInt());
            else if  (op.equals("query")) {
                int no = sc.nextInt();
                int s = cms.query(no);
                System.out.println("the score for "+no+" is : "+s);
            }
        }
        cms.statistic();
    }
}


class Student {
    int id;
    int grade;

    public Student(int id, int grade) {
        super();
        this.id = id;
        this.grade = grade;
    }


    public boolean equals(Student s) {
        if (s.id == id) {
            return true;
        }
        return false;
    }
}

class CourseManagementSystem {
    ArrayList<Student> list = new ArrayList();

    public void add(int id, int grade) {
        Student newS = new Student(id, grade);

        for (Student s : list) {
            if (s.id == id) {
                System.out.println("the student already exists");
                return;
            }
        }

        list.add(newS);
    }

    public void delete(int no) {
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i).id == no) {
                list.remove(i);
                return;
            }
        }

        System.out.println("no such student");
    }

    public int query(int no) {
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i).id == no) {
                return list.get(i).grade;
            }
        }

        System.out.println("no such student");

        return -1;
    }

    public void statistic() {
        int[] gs = new int[6];

        for(Student s : list) {
            int g = s.grade;
            if(g >= 0 && g <= 59) {
                gs[0]++;
            }else if(g >= 60 && g <= 69) {
                gs[1]++;
            }else if(g >= 70 && g <= 79) {
                gs[2]++;
            }else if(g >= 80 && g <= 89) {
                gs[3]++;
            }else if(g >= 90 && g <= 100) {
                gs[4]++;
            }
        }
        System.out.println("[0-59] : " + gs[0]);
        System.out.println("[60-69] : " + gs[1]);
        System.out.println("[70-79] : " + gs[2]);
        System.out.println("[80-89] : " + gs[3]);
        System.out.println("[90-100] : " + gs[4]);
    }
}

*/
